Drainage channel



FIG. 1 is a top front isometric view of a drainage channel showing my new design;

FIG. 2 is a bottom rear isometric view thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is a right side elevational view thereof.

The left side elevational view of the drainage channel is a mirror image of the right side elevational view. The drainage channel is shown broken away with broken line interruptions in FIGS. 1 to 3 in order to indicate that a specific length of drainage channel forms no part of the claimed design. 

The ornamental design for the drainage channel, as shown and described. 